sadāśivasuto nāmnā nāgaraḥ puruṣottamaḥ
vaidya-vaṁśodbhavo nāmnā dāma yo vallabho vraje

Nāgara Puruṣottama was previously the cowherd named Dāma in Vraja. He has now taken birth in a vaidya family as the son of Sadāśiva. (Gaura-gaṇoddeśa-dīpikā 131)

Dāma was one of the twelve gopālas and a companion of Kṛṣṇa in His childhood pastimes in Vraja. In the eleventh chapter of the Ādi-līlā of Caitanya Caritāmṛta, Kṛṣṇadāsa Kavirāja Gosvāmī has listed Puruṣottama Dāsa amongst the foremost devotees of Lord Nityānanda.

Sadāśiva Kavirāja was a great personality. Puruṣottama Dāsa was his son. From birth, Puruṣottama Dāsa was absorbed in the service of the lotus feet of Lord Nityānanda, and he always engaged in childlike play with Lord Kṛṣṇa. His son was named Śrī Kānu Ṭhākura, a very respectable gentleman. His body was saturated with the nectar of love for Lord Kṛṣṇa. (Caitanya Caritāmṛta 1.11.38-40)

Vṛndāvana Dāsa Ṭhākura has also named Puruṣottama Dāsa as one of Nityānanda Prabhu’s chief associates.

Sadāśiva Kavirāja was very fortunate to have a son like Puruṣottama Dāsa. Puruṣottama Dāsa had no external consciousness of his body, for Nityānanda Prabhu dwelled in his heart. (Caitanya Bhāgavata 3.5.741-2)

For four generations, eternally perfect direct associates of Mahāprabhu—Kaṁsāri Sen, Sadāśiva Kavirāja, Puruṣottama Ṭhākura and Kānu Ṭhākura—appeared in the family of Puruṣottama Ṭhākura. Such an occurrence is quite uncommon. The Gaura-gaṇoddeśa-dīpikā identifies Kaṁsāri Sena as Ratnāvalī and Sadāśiva Kavirāja as Candrāvalī (156).

Puruṣottama Ṭhākura’s wife was named Jāhnavā Devī. She died while her son, Kānu Ṭhākura, was just a young child. Nityānanda Prabhu named the boy Śiśu Kṛṣṇadāsa. It is said that Nityānanda Prabhu’s wife Jāhnavā Devī adopted Kānu and took him with her to Vṛndāvana. Some say that he was also one of the twelve gopālas. Once while in Vṛndāvana when Kānu Ṭhākura was dancing in kīrtana, his ankle bell flew off. He vowed that he would make his residence wherever the ankle bell was recovered. The ankle bell was found in the town of Bodhakhānā in Jessore district and so he established his Sripat there. Madhavācārya (Mādhava Caṭṭopadhyāya) of Jirat was Puruṣottama Ṭhākura’s disciple.

Śrīla Bhakti Siddhānta Sarasvatī Gosvāmī Ṭhākura has the following to say about Puruṣottama Ṭhākura’s Sripat: “Puruṣottama Dāsa Ṭhākura lived at Sukhasagar, midway between the Chakdah and Simurali villages of Nadiya district. The deities he served were formerly in Beledanga village, but when the temple fell into the river, the deities were taken to Sukhasāgara. That temple was also swallowed by the Ganges and so the deities were brought with Jāhnavā Mātā’s deity to Sahebdanga Berigram. Since that place was also destroyed, all the deities were again moved about three or four miles to the village named Chanduregram, on the banks of the Ganges about one mile up from Palpara.” (Anubhāṣya to Caitanya Caritāmṛta 1.11.39)

Devakīnandana Dāsa, the author of the Vaiṣṇava-vandanā, was Puruṣottama Ṭhākura’s disciple. There he writes:

I worship Sadāśiva Kavirāja with great attentiveness. He was constantly intoxicated with love and had no external consciousness. I worship my worshipable lord, Puruṣottama Ṭhākura. Who can count his incomparable qualities? He was merciful to those who were devoid of virtue, displaying the natural power of his compassion. When only seven years old, he was so intoxicated with love for Kṛṣṇa that he danced in a way that enchanted the entire world.

The following supplementary information is given in the Gauḍīya Vaiṣṇava Abhidhāna:

“Some people say that Puruṣottama’s surname was Nāgara, while others say that the name Nāgara comes from the name of the area where he lived. Since fourteen villages Beledanga, Berigram, Sukhasagar, Chandure, Manasapota, Palpara, etc. are under one administrative unit of Pancanagara, this area is sometimes called Nagaradesh. Once Puruṣottama ate snake poison when in a trance without experiencing any ill effects. This was a source of great astonishment to all those who witnessed it. Many of Nityānanda Prabhu’s associates often displayed such miraculous powers.